The present invention relates to a solid-state high power amplifier arrangement used for a television transmitter, for example, and more particularly to such an arrangement including a plurality of power amplifier units and compulsory air cooling means.
Conventionally, a solid-state high power amplifier arrangement is constructed, as shown in FIG. 1 and FIGS. 2(a) and 2(b), for example.
FIG. 1 shows a plurality of transistor power amplifier units (referred to as "TRPA units") 11; a plurality of power supply units (referred to as "PS units") 12 for supplying electric power; a combiner unit 13 for combining outputs of the plurality of TRPA units 11 to obtain a high power output; and a shelf 15 including individual parts 15a to 15i for accommodating the aforementioned units 11 and 13.
As shown in FIG. 1, each TRPA unit 11 is accommodated in the shelf 15 through guide rails 15f and, at the same time, a plug 11b projected from the unit 11 is connected with a socket 15g. On the other hand, each PS unit 12 is also accommodated on the shelf 15 and the output of the PS unit 12 is connected through the cable 15h with the socket 15g of bracket 15i so that the TRPA unit 11 and the PS unit 12 are electrically connected. Moreover, the combiner unit 13 fixed in advance on the shelf 15 is connected to the TRPA unit 11 through the socket 13a, the plug 11a and a U link 14.
In FIGS. 2(a) and 2(b) showing sectional diagrams of the arrangement of FIG. 1, cooling air 16 is supplied from the side of an air chamber 15a and is distributed into the heat sinks 11c of the TRPA units 11 and into the PS units 12. The cooling air 16 blown into the head sinks 11c cools heating elements 11d through the heat sinks 11c and, then air 16, is exhausted through an air chamber 15b and an exhaust duct 15d. On the other hand, the cooling air blown to the PS unit 12 is exhausted through an air chamber 15c and an exhaust duct 15e.
In the aforementioned conventional solid-state high power amplifier arrangement shown in FIGS. 2(a) and 2(b), space M' between the TRPA unit 11 and the PS unit 12 has to be enlarged in a unit-accommodating direction because of the presence of the bracket 15i and the cable 15h. Moreover, space N' between the TRPA unit 11 and the combiner unit 13 has to be enlarged because of the presence of the air chamber 15b. Still moreover, the total width P' becomes enlarged because of the presence of the heat sinks 11c. In addition to the units 11 and 12, on the other hand, the cable 15h, the U links 14 and the bracket 15i are required for electric connections, and the air chambers 15b and 15c and the exhaust ducts 15d are required for protection against the heat of the exhaust air.
The aforementioned requirements of the conventional arrangement increase cost of the parts and the number of assembling and wiring steps, and, much time is necessary to insert or pull out the individual units. Further, the TRPA units 11 are heavy due to the heaviness of heat sinks 11c so that maintenance of the units 11 is troublesome. Incidentally, the heat sinks 11c are troubled by deteriorating the cooling effect because temperature of the cooling air at the downstream is raised depending upon the flow direction of the cooling air. Moreover, the conventional arrangement is further troubled with a safety risk because the U links interconnecting the high power outputs are disposed at the front.